The Garage

Motocross

Stock-size parts in stock at MotoSport

GasGas MC 85 2027

Motocross, 85cc 2T, US version

Verified

From the owner’s manual: premix 40:1, p. 124; coolant 0.8 l, p. 120; front tire 70/100-17 M/C 40M TT, p. 124; rear tire 90/100-14 M/C 49M TT, p. 124. Checked 16 Oct 2026.

Model year on file: 2027 only. Other years are added as their manuals are read.

No CPSC recall found for the 2027 GasGas MC 85, checked 2026-10-15. Recalls

Spec card PDF

Gearing

4 of 5 filled

Stock front sprocket
13T
Verified, read off the manual page: Manual p. 123 · checked 2026-09-28 source [1]
Stock rear sprocket
46T
Verified, read off the manual page: Manual p. 123 · checked 2026-09-28 source [1]
Chain pitch
428
Calculated, not printed: The trade name of the printed size 1/2 x 5/16" · Manual p. 123 · checked 2026-09-28 source [1]
Stock chain links
Not yet verified
Stock final drive ratio
3.54 : 1
Calculated, not printed: Calculated from the stock sprockets, printed on manual p. 123

Wheels and tires

4 of 4 filled

Front rim
17 x 1.4
Research level: Spec sheet (research) · checked 2026-09-27 source [2]
Rear rim
14 x 1.6
Research level: Spec sheet (research) · checked 2026-09-27 source [2]
Front tire
70/100-17 M/C 40M TT
Verified, read off the manual page: Manual p. 124 · checked 2026-09-28 source [1]
Rear tire
90/100-14 M/C 49M TT
Verified, read off the manual page: Manual p. 124 · checked 2026-09-28 source [1]

Suspension

5 of 7 filled

Fork
WP XACT 5543 (air fork)
Verified, read off the manual page: Manual p. 123 · checked 2026-09-28 source [1]
Fork travel
278 mm (10.94 in)
Verified, read off the manual page: Manual p. 123 · checked 2026-09-28 source [1]
Shock travel
289 mm (11.38 in)
Verified, read off the manual page: Manual p. 123 · checked 2026-09-28 source [1]
Stock fork spring rate
Not yet verified
Stock shock spring rate
Not yet verified
Static sag, bike only
30 mm (1.18 in)
Verified, read off the manual page: Manual p. 126 · checked 2026-09-28 source [1]
Race sag, rider on
100 mm (3.94 in)
Verified, read off the manual page: Manual p. 126 · checked 2026-09-28 source [1]

Fluids and capacities

3 of 3 filled

Coolant capacity
0.8 l (≈ 27.1 fl oz, converted by MotoXSports)
Verified, read off the manual page: Manual p. 120 · checked 2026-09-28 source [1]
Premix ratio
40:1
Verified, read off the manual page: Manual p. 124 · checked 2026-09-28 source [1]
Fuel capacity
5.4 l (≈ 1.43 gal, converted by MotoXSports)
Verified, read off the manual page: Manual p. 124 · checked 2026-09-28 source [1]

Service specs

6 of 6 filled

Gearbox oil
0.50 l (0.132 liq. galUS); Engine oil (15W/50), Partially synthetic
Verified, read off the manual page: Manual p. 120 · checked 2026-10-16 source [1]
Fork oil
Fork oil (48601166S1) (SAE 4): right outer assembly 363 ±10 ml (12.27 ±0.34 fl. ozUS); left outer assembly 100 ±20 ml (3.38 ±0.68 fl. ozUS)
Verified, read off the manual page: Manual p. 125 · checked 2026-10-16 source [1]
Brake fluid
DOT 5.1
Verified, read off the manual page: Manual p. 137 · checked 2026-10-16 source [1]
Coolant type
COOLANT M3.0, recommended supplier MOTOREX®; antifreeze protection to at least −25 °C (−13.0 °F)
Verified, read off the manual page: Manual p. 137 · checked 2026-10-16 source [1]
Fuel octane
Super unleaded (98 octane)
Verified, read off the manual page: Manual p. 135 · checked 2026-10-16 source [1]
Idle speed
1,500 rpm … 2,000 rpm (25.00 Hz … 33.33 Hz)
Verified, read off the manual page: Manual p. 119 · checked 2026-10-16 source [1]

Maintenance

3 of 3 filled

Tire pressure (off-road)
1.0 bar (14.5 psi) front and rear
Verified, read off the manual page: Manual p. 124 · checked 2026-09-28 source [1]
Chain slack
43-46 mm (1.69-1.81 in)
Verified, read off the manual page: Manual p. 67 · checked 2026-09-28 source [1]
Spark plug and gap
BRISK AR10C, gap 0.70 mm
Verified, read off the manual page: Manual p. 119 · checked 2026-09-28 source [1]

Dimensions

3 of 3 filled

Seat height
845 mm (≈ 33.3 in, converted by MotoXSports)
Verified, read off the manual page: Manual p. 123 · checked 2026-09-28 source [1]
Wheelbase
1282 mm (≈ 50.5 in, converted by MotoXSports)
Verified, read off the manual page: Manual p. 123 · checked 2026-09-28 source [1]
Weight (weight without fuel approx. (MC 85 17/14))
68 kg (≈ 150 lb, converted by MotoXSports)
Verified, read off the manual page: Manual p. 124 · checked 2026-09-28 source [1]
Solid marks are owner's-manual pages; hollow marks are manufacturer web or spec-sheet figures still waiting on a manual page. Last reviewed 2026-10-16. Rows marked not yet verified are blank on purpose.

Buying parts

The stock sizes and specs this bike left the factory with, each with its source. Take them to any shop.

Retailer links below are affiliate links: we may earn a commission, at no cost to you, and it never changes the specs. Affiliate disclosure.

Chain
Chain pitch 428 Owner's manual p. 123428 chains at MotoSport428 master links at MotoSport
Sprockets
Stock front sprocket 13T Owner's manual p. 123Stock rear sprocket 46T Owner's manual p. 12313T front sprockets at MotoSport46T rear sprockets at MotoSport
Tires
Front tire 70/100-17 M/C 40M TT Owner's manual p. 124Rear tire 90/100-14 M/C 49M TT Owner's manual p. 124Front tires 70/100-17 at MotoSportTubes 70/100-17 at MotoSportRear tires 90/100-14 at MotoSportTubes 90/100-14 at MotoSport
Coolant
Coolant capacity 800 ml (27.1 fl oz) Owner's manual p. 120Coolant at MotoSport

In stock at MotoSport

Prices from MotoSport’s catalog of Oct 26, 2026; check today’s price before you buy.

Front tire, stock size 70/100-17

Rear tire, stock size 90/100-14

Prices and stock from MotoSport's product catalog on Oct 26, 2026; they change, so check the price at MotoSport before you buy. Products are chosen by exact stock size, code or oil viscosity from the specs above, known brands first, then price. We have not tested them.

3 part specs not yet verified; see data coverage.

Tools for this bike

Compare with

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Service schedule

47 rows from the owner's manual schedule, pp. 30-31, counted in hours, at these intervals:

  • After one operating hour
  • Every 15 operating hours
  • Every 45 operating hours
  • Every 90 operating hours
  • Every 24 months

Check what's due or track it in My Bike. Buying one used? The hours check lists what the schedule calls for by its meter reading.

Riding

Where kids can ride: tracks and areas whose own pages mention young riders.

Gearing calculator

Gearing for this bike

Put your current gearing in Setup A and the setup you are considering in Setup B. Everything updates as you type.

Pick a bike to fill both setups with its stock sprockets.

Front sprockets 8–16 teeth, rear 34–60. Values outside that range are brought back to the nearest limit.

Setup A — what you run now
Setup B — what you are thinking about
Final drive ratio

— — : 1

—
Pull at the wheel—
Top speed—
Ratio change—
A —
B —
Taller · more speed Shorter · more pull

—

Changing the rear sprocket changes the chain length too. The chain length calculator works it out from the chain you have now, with where the axle ends up.

Ratios are exact. The chain figure is an estimate of roughly one link per two teeth of change — confirm against your manual before ordering.

What's missing

25 of 30 fields read off a manual page.

Not yet verified (3): chain links, fork spring rate, shock spring rate.

From a spec sheet, awaiting a manual page (2): front rim, rear rim.

See coverage for every bike

Sources

  1. 1
    GASGAS Owner's Manual 2027 MC 85, Item no. 3215284en (12/08/2026); owner-supplied copy from the KTM Group print-on-demand portalpp. 67, 119, 120, 123, 124, 125, 126, 135, 137Manual page, verified. Covers stock front sprocket, stock rear sprocket, chain pitch, front tire, rear tire, fork, fork travel, shock travel, static sag, bike only, race sag, rider on, coolant capacity, fuel capacity, premix ratio, tire pressure (off-road), chain slack, spark plug and gap, seat height, wheelbase, weight (weight without fuel approx. (MC 85 17/14)), weight, as labelled, gearbox oil, fork oil, brake fluid, coolant type, fuel octane, idle speed; checked 2026-10-16.
  2. 2
    GASGAS 2027 MC 85 17/14 technical specifications (gasgas.com, US)Manufacturer web or spec sheet, research level. Covers front rim, rear rim; checked 2026-09-27.

Always confirm against the manual for your exact year before ordering parts or setting up suspension. Torque specs are deliberately not published here. How we verify a value.

Your manual prints something different? Report a value with the page it is on; every fix is listed in the corrections log.

My settings

Date / track
Sprockets run
Race sag / free sag
Fork air pressure or spring
Fork clickers (compression / rebound)
Shock clickers (low / high / rebound)
Tire pressures (front / rear)
Notes
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